CLINICAL Painful pustular dactylitis in an elderly patient José Tiago Teixeira, Carina Afonso, Maria Bernardete Machado, Paulo Morais Case Question 1 Answer 2 A man, 74 years of age, presented with What differential diagnoses should be Acrodermatitis continua of Hallopeau (ACH), dactylitis on the first, second and fourth considered in this case? a localised pustular psoriasis, is the most digits of his left hand, characterised likely diagnosis. It is a rare, chronic, relapsing by glossy erythema, oedema, pustules Question 2 condition, often triggered by local trauma or and yellowish scales. Additionally, What is the most likely diagnosis in this infection. ACH occurs in all age groups, but there was onychodystrophy, subungual patient? is more prevalent in middle-aged women.1,2 hyperkeratosis, almost complete onycholysis and pustules on the nail bed (Figure 1). The Question 3 Answer 3 lesions first appeared two months ago and What is the aetiology of this dermatosis? This dermatosis is considered a variant of have been progressively worsening since, How is it diagnosed? pustular psoriasis; however, the aetiology is spreading proximally. There were no similar not completely understood. Inflammatory, lesions and no evidence of psoriasis on Question 4 infectious and neural aetiologies have full‑skin examination. The patient also noted What are the available treatments for this been proposed. The diagnosis must functional incapacity of the affected digits, condition? be established on the basis of clinical along with pain to the touch, but denied features, and biopsy of the lesions may hand trauma prior to the appearance of the Question 5 be performed. Other investigations to lesions. What is the prognosis of this skin consider include Herpes simplex virus His past medical history included disorder? polymerase chain reaction (PCR) swab arterial hypertension, type 2 diabetes test, and Gram stain smear and culture of mellitus, dyslipidaemia and chronic alcohol Answer 1 pustular fluid to exclude bacterial infection. consumption. His medications included The main diagnoses to consider in this A potassium hydroxide preparation of the insulin glargine, amlodipine, acarbose and case are listed in Table 1.1–5 pustules can exclude fungal infection.3 simvastatin. A B C Figure 1. Clinical appearance of the lesions A. Dorsal; B. Palmar; C. Lateral REPRINTED FROM AFP VOL.46, NO.6, JUNE 2017 397 CLINICAL PAINFUL PUSTULAR DACTYLITIS Table 1. Main differential diagnoses to be considered in the present case1–5 Answer 5 ACH usually responds poorly Disease Clinical characteristics to therapy, and spontaneous Acrodermatitis Sterile pustules in an erythematous base, usually with desquamation improvement is rare. There is no continua of There may be onychodystrophy, anonychia or even osteolysis of the phalynx treatment that can ensure a long Hallopeau More than one digit may be affected remission.1–7 In longstanding cases, Lesions start on their distal portion, spreading proximally over time osteolysis can occur, and generalised Staphylococcal Usually as secondary skin infection of pre-existing lesions pustular psoriasis may develop, infection Paronychia may be present including von Zumbusch’s psoriasis, Small vesicles or pustules in an erythematous base especially in the elderly.3,5 A yellowish crust may develop over the ruptured lesions Case continued Herpetic May exist a prodrome of fever several days before whitlow Pain and edema of usually one digit The skin biopsy revealed Vesicular lesions with clear fluid, clustered, in an erythematous base histopathological findings consistent There may be extension of the infection to the nail bed with pustular psoriasis, which, along with the clinical presentation, Candidal Acute paronychia is characterised by edema, erythema and tenderness of paronychia nail folds supported the diagnosis of ACH. Purulent material under the nail fold is common, which may drain if Laboratory tests found macrocytosis, compressed. Onycodystrophy may occur anisocytosis, elevated transaminases, Pompholyx Itching and burning sensation of the hands and/or feet γ‑glutamyltransferase and eczema Initially small vesicles with clear fluid may coalesce to form bullae hypercholesterolemia. Considering There is often subsequent desquamation the comorbidities, laboratory abnormalities and extension of the Dermatitis Irritant dermatitis: lesions observed in the following • Onset of symptoms: Minutes to weeks after exposure appointment, combined treatment • Itching, pain, macular erythema, scalded appearance and hyperkeratosis with betamethasone dipropionate Contact dermatitis: • Onset of symptoms: Within days – longer if it’s the first contact 0.05% cream once daily, a cream • Presentation change with the responsible agent containing ichthyol, salix alba extract, • Erythematous base with vesicles or papules salicylic acid and provitamin D3 twice • Pruritic, hyperkeratotic plaques in chronic dermatitis daily and topical PUVA was started. The patient was re‑evaluated Squamous cell Mostly asymptomatic, the lesions may bleed or be painful three months later, showing no carcinoma Macula, plaque or node with or without desquamation, hyperkeratosis and erosions improvement of the disease. May be single or multiple lesions Therefore, treatment was changed to 0.05% clobetasol propionate under occlusion and 10% salicylic acid in petrolatum ointment each applied Answer 4 under occlusion. When adequate, the once daily. topical corticosteroid can be tapered to Because of the rarity of ACH and the once or twice a week. Topical vitamin D Key points limited evidence, mainly obtained from analogues and calcineurin inhibitors • It is of the utmost importance case reports, definite conclusions about can be used as adjunct or maintenance that other diseases are excluded the treatment are difficult to obtain, therapy, once or twice a week. If local before making a firm diagnosis making the best approach unclear.6,7 treatment fails, topical psoralen and of ACH. Searching for infection Given the link to pustular psoriasis, many ultraviolet A (PUVA) therapy, narrowband is essential to the differential anti-psoriatic agents have been tried.3 UVB and systemic drugs (eg methotrexate, diagnosis, especially when there is Antibiotics and antifungal agents can ciclosporin, acitretin) can be used. Although no response to antibiotics. be used if there is suspected infection. not approved by the Pharmaceutical • There is limited evidence regarding Usually, high or ultra-high potency topical Benefits Scheme, adalimumab, infliximab the treatment of this disease. corticosteroids are the first treatment or etanercept may be attempted when Even when adequately treated, it choice, and can be applied once to twice there is no adequate response to any of is very difficult to achieve a lasting daily over two to four weeks, preferably the other treatments.3,6,8 remission. 398 REPRINTED FROM AFP VOL.46, NO.6, JUNE 2017 PAINFUL PUSTULAR DACTYLITIS CLINICAL Authors José Tiago Teixeira MD, Family Medicine Trainee, USF Viriato, Viseu, Portugal. [email protected] Carina Afonso MD, Family Medicine Trainee, USF Viriato, Viseu, Portugal Maria Bernardete Machado MD, Family Medicine Trainee, USF Infante D. Henrique, Viseu, Portugal Paulo Morais MD, Dermatologist, Department of Dermatovenereology, Centro Hospitalar Tondela- Viseu, Viseu, Portugal Competing interests and funding: None. Provenance and peer review: Not commissioned, externally peer reviewed. References 1. Jo SJ, Park JY, Yoon HS, Youn JI. Case of acrodermatitis continua accompanied by psoriatic arthritis. J Dermatol 2006;33:787–91. 2. Waller JM, Wu JJ, Murase JE, Dyson SW, Kelly KM. Chronically painful right thumb with pustules and onycholysis. Clin Exp Dermatol 2007;32:619–20. 3. Sehgal VN, Verma P, Sharma S, et al. Acrodermatitis continua of Hallopeau: Evolution of treatment options. Int J Dermatol 2011;50:1195–211. 4. Wolff K, Johnson RA, Saavedra AP. Fitzpatrick’s color atlas & synopsis of clinical dermatology. 7th edn. New York: McGraw Hill Education, 2013. 5. Yerushalmi J, Grunwald MH, Hallel-Halevy D, Avinoach I, Halevy S. Chronic pustular eruption of the thumbs. Diagnosis: Acrodermatitis continua of Hallopeau (ACH). 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